1. Field of the Invention
Embodiments of the invention generally relate to a load lock chamber for transferring large area substrates into a vacuum processing environment.
2. Description of the Related Art
When processing substrates to manufacture flat panel displays, organic light emitting displays (OLEDs), solar panels, and semiconductors, multiple processes may be performed in order to achieve the desired end product. Some of the processes may be performed under vacuum. Examples of vacuum processes that may be used include plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), etching, and others.
When multiple vacuum processes are performed, it may be beneficial to have the different chambers coupled to a common transfer chamber. By coupling a plurality of processing chambers to a common vacuum chamber, the substrate may have a first process performed on it in a first chamber. Thereafter, the substrate may be removed into the transfer chamber and then inserted into the second chamber where a second, separate process may occur. To reduce the evacuation time, the transfer chamber may be maintained at a vacuum level similar to the vacuum level of the processing chambers.
Prior to and/or after the vacuum processing, the substrates may move through a non-vacuum environment. The substrates may enter and exit the system through a factory interface that is maintained at atmospheric pressure. Thus, there may be an abrupt change in vacuum level between the transfer chamber and the factory interface.
A load lock chamber may be used to reduce and/or prevent the abrupt pressure change. The load lock chamber may be evacuated to a pressure substantially identical to the pressure of the transfer chamber to permit the substrate enter and/or exit the transfer chamber. Additionally, the load lock chamber may be vented to atmosphere so that the pressure of the load lock chamber is substantially identical to the pressure of the factory interface. Thus, the load lock chamber may reduce and/or prevent an abrupt pressure change between the factory interface and the transfer chamber.
Therefore, there is a need in the art for a load lock chamber capable of maintaining a vacuum.